import numpy as np
arr = np.array([[1,2,3],[4,5,6],[7,8,9],[10,11,12]])
print('4x3的整数数组: \n',arr)
print('数组的ndim属性: \n',arr.ndim)
print('数组的shape属性: \n',arr.shape)
print('数组的size属性: \n',arr.size)
print('数组的dtype属性: \n',arr.dtype)